Related papers: Slow crossover in YbXCu4 intermediate valence comp…
We study valence fluctuations at finite temperatures in the extended periodic Anderson model, where the Coulomb interaction between conduction and localized $f$-electrons is taken into account, using dynamical mean-field theory combined…
Ferroquadrupole order associated with local $4f$ atomic orbitals of rare earth ions is a realization of electronic nematic order. However, there are relatively few examples of intermetallic materials which exhibit continuous ferroquadrupole…
We present an extension of the non-crossing approximation (NCA), which is widely used to calculate properties of Anderson impurity models in the limit of infinite Coulomb repulsion $U\to\infty$, to the case of finite $U$. A self-consistent…
Applying the local density and dynamical mean field approximations to paramagnetic \gamma-iron we revisit the problem of theoretical description of magnetic properties in a wide temperature range. We show that contrary to \alpha-iron, the…
Extended x-ray absorption fine-structure (EXAFS) measurements have been carried out on Ni$_{50}$Mn$_{35}$Sn$_{15}$ in the austenitic and martensitic phase. The temperatures associated with structural and magnetic phase transformations are…
The compound LiAl_yTi_(2-y)O_4 undergoes a metal-to-insulator transition for y_c ~0 .33. This system, in the absence of strong electronic correlations, is a prototypical example of quantum site percolation. However, it is known that the…
$\alpha$-YbAlB$_4$ is the locally isostructural polymorph of $\beta$-YbAlB$_4$, the first example of an Yb-based heavy fermion superconductor which exhibits pronounced non-Fermi-liquid behavior above $T_{\rm c}$. Interestingly, both…
We report the temperature dependence of the Yb valence in the geometrically frustrated compound $\mathrm{YbB_4}$ from 12 to 300 K using resonant X-ray emission spectroscopy at the Yb $L_{\alpha_1}$ transition. We find that the Yb valence,…
An increasing number of Yb-based compounds fulfill the conditions for the investigation of hyperfine electro-nuclear coupling effects related to 171-Yb and 173-Yb isotopes. Among them, the lack of magnetic order down to the milikelvin range…
We present the high-precision magnetization data of the valence fluctuating heavy fermion superconductor $\beta$-YbAlB$_4$ in a wide temperature range from 0.02 K to 320 K spanning four orders of magnitude. We made detailed analyses of the…
The UCu(5-x)Pd(x) system exhibits non-Fermi liquid (NFL) in the thermodynamic and transport properties at low temperatures for Pd concentrations 0.9 <~ x <~ 1.5. The local structure around the U, Cu, and Pd atoms has been measured for 0 <=…
The transition--metal oxide CaCu$_3$Ru$_4$O$_{12}$ with perovskite--type structure shows characteristic properties of an intermediate--valence system. The temperature--dependent susceptibility exhibits a broad maximum around $150 - 160$ K.…
We have studied the Knight shift $K(\vec r, T)$ and magnetic susceptibility $\chi(T)$ of heavy electron materials, modeled by the infinite U Anderson model with the NCA method. A systematic study of $K(\vec r, T)$ and $\chi(T)$ for…
We study theoretically the class of mixed-valent Kondo insulators, employing a recently developed local moment approach to heavy Fermion systems using the asymmetric periodic Anderson model (PAM). Novel features in spectra and transport,…
We report a Determinant Quantum Monte Carlo investigation which quantifies the behavior of the susceptibility and the entropy in the framework of the periodic Anderson model (PAM), focussing on the evolution with different degree of…
We report on the physical properties of the series Ce_(1-x)La_xIr_2B_2 (x D 0-0.9), obtained by means of magnetization, heat capacity and electrical resistivity measurements as a function of temperature (down to 0.7 K for the latter two…
Polycrystalline samples of the solid solution Ce2Cu2-xNixIn were studied by means of x-ray powder diffraction, magnetic susceptibility and electrical resistivity measurements performed in a wide temperature range. Partial substitution of…
The weak itinerant ferromagnetic behavior of Y$_2$Ni$_7$ is investigated through magnetic, transport and calorimetric measurements. The low value of saturation moment, large Rhodes-Wohlfarth ratio, large value of the linear term in heat…
We present a systematic study of the variations of the ^{7}Li NMR properties versus magnetic defect concentration up to 0.83 mol% within the spinel structure of polycrystalline powder samples and a collection of small single crystals of…
Low temperature ac magnetic susceptibility measurements of the coexistent antiferromagnetic superconductor YbPd2Sn have been made in hydrostatic pressures < 74 kbar in moissanite anvil cells. The superconducting transition temperature is…